Vent stuck open on GE JVM3670SF08 over-counter microwave oven

We have one of these -- installed in 2008. It's a pretty nice appliance, easy to use. It has a vent fan that blows steam (etc) from the stove to an exhaust vent outside the house, and when the fan (or the microwave oven) is running, a vent above the microwave door angles open to draw steam/fumes/etc that drift up past the front of the microwave. The other day I noticed that the upper vent was stuck open, as seen in the photo on the right. I climbed up and saw the problem -- a broken plastic part (photo below). See the piece my finger's on, with the screw in it? It's supposed to be rotated back 90° or so away from you -- that is, what's nearly horizontal should instead be vertical. It's like the spring just pulled too hard and tore that whole part loose. And a look on top of the appliance showed more cracks -- a screw at upper right looks like maybe it was over-tightened, too.

To take it off, I undid 3 downward-pointing screws, then shoved the grille assembly slightly to the left. It then came straight out, except for one piece that simply fell to the floor, and another that had broken off completely and was still wedged. The whole grille sub-assembly had a thin coating of grease.

Well, I thought, guess I'll go looking for the part. I found the model number -- JVM3670WF08 -- on the inside of the microwave oven, and did a web search on that plus the word "parts".

Some websites offered parts for JVM3670WF06 or something like this, apparently a countertop model. But one site, partselect.com, had the right model number, and this picture gave me enough information to order the grille sub-assembly confidently. Just for kicks, I searched on the part number (WB07X10444) once I had that info. Sure enough, some other websites had it at a lower price. But since the partselect.com guys showed me what the part was, I went ahead and ordered from them. I want that website to be around the next time I need a part.

Meanwhile, I used some spray cleaner to get rid of the grease, and krazy glue™ or similar to put 3 or 4 of the cracks back together. That's probably enough to hold 'til the new part arrives.